Display device

ABSTRACT

A display is rotatably supported by a hinge portion as a support portion. The hinge portion has an engaging portion for performing engagement when the display is rotated to a predetermined using position. The engaging portion is constructed so as to perform the engagement in plural engaging places when the display is rotated to the predetermined using position. The engaging portion has a fixing member and a rotating member constituting the hinge portion. One of the fixing member and the rotating member has plural convex portions, and the other has plural concave portions. These plural convex portions and concave portions are arranged so as to be engaged with each other. Thus, durability of the engaging portion is improved, and GND ability can be improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device for rotatablysupporting a display.

2. Background

There is conventionally a case in which the display is rotatablyarranged in a vehicle, etc. For example, the display device of this kindis disclosed in JP-A-2-86277 (page 2 and FIG. 2). In this literature,hinges are arranged on both sides of the display.

In the above literature, the position of the display is steplesslyadjusted. The display device of another type different from such astepless adjusting type is locked in a predetermined using position. Thedisplay device of this type is shown in FIGS. 11 to 13.

In FIG. 11, the display 100 is supported by hinges 102, 104 on both thesides. FIG. 12 typically shows the hinge 102. The hinge 102 has anengaging means. The engaging means is constructed by a bracket 106 and arotating spring 108. The bracket 106 is fixed and rotatably supports ahinge shaft. The rotating spring 108 is arranged so as to be rotatedtogether with the hinge shaft. One concave portion 110 is arranged inthe bracket 106, and one convex portion 112 is arranged in the rotatingspring 108. When the display 100 is rotated and reaches a predeterminedusing position, the convex portion 112 reaches the concave portion 110.As shown in FIG. 13, the convex portion 112 and the concave portion 110are then engaged with each other. Thus, the position of the display 100is locked. As shown by a dotted line in the cross-sectional view of FIG.13, when the convex portion 112 and the concave portion 110 are shifted,the convex portion 112 is interposed between the bracket 106 and therotating spring 108. Accordingly, the rotating spring 108 is elasticallydeformed and warped. Thus, the convex portion 112 is pushed against thebracket 106 by spring pressure.

As mentioned above, the display device conventionally has the engagingmeans constructed by a combination of one concave portion and one convexportion. Such an engaging means is arranged in the hinge on one side ofthe display. Otherwise, the engaging means of a similar construction isarranged in the hinges on both the sides of the display.

However, as shown by the dotted line in the cross-sectional view of FIG.13, in the conventional display device, the convex portion is pressedagainst the bracket by the spring pressure except for an engaging place,and is slid. Therefore, when the number of using times is increased,wearing of the convex portion is caused and there is a tendency in whichholding force of the engaging portion is reduced.

Further, in the conventional display device, there are many cases inwhich the housing of the device is utilized for a electric GND(grounding) and a GND level is set to the housing of the device.However, in the construction for obtaining contact between metals by theengaging portion (concave and convex), there is a case in which theimpedance of the engaging portion is raised since the contact isinsufficient. In this case, GND force is reduced (the GND level becomesunstable). Furthermore, the spring force is reduced in accordance with ause with the passage of time and the contact pressure of the engagingportion is reduced. There is a tendency in which the GND force isfurther reduced. Thus, in the conventional display device, there wasroom for an improvement of electric performance with respect to GND.

SUMMARY OF THE INVENTION

The present invention is made under the above background. An purpose ofthe present invention is to provide a display device able to improvedurability of the engaging structure and also improve the electricperformance.

A display device of the present invention comprises a display, a supportportion for rotatably supporting the display, and at least one engagingportion for performing engagement when the display is rotated to apredetermined using position, the engaging portion being constructed soas to perform the engagement in plural engaging places when the displayis rotated to the predetermined using position.

As described hereafter, other aspects of the invention exist. Thus, thissummary of the invention is intended to provide a few aspects of theinvention and is not intended to limit the scope of the inventiondescribed and claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated in and constitute a part ofthis specification. The drawings exemplify certain aspects of theinvention and, together with the description, serve to explain someprinciples of the invention.

FIG. 1 is an exploded perspective view of a display device in anembodiment of the present invention.

FIG. 2 is an exploded perspective view of a right-hand hinge portion.

FIG. 3 is an exploded perspective view of a left-hand hinge portion.

FIG. 4 is a perspective view showing the display device in a closingstate.

FIG. 5 is a perspective view showing the display device in asemi-opening state.

FIG. 6 is a perspective view showing the display device in a fullopening state.

FIG. 7 is a view showing a modified example of the hinge portion.

FIG. 8 is a view showing a modified example of the hinge portion.

FIG. 9 is a view showing a modified example of the hinge portion.

FIG. 10 is a view showing a modified example of the hinge portion.

FIG. 11 is a view showing a conventional display device.

FIG. 12 is a view showing the conventional display device.

FIG. 13 is a view showing the conventional display device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description refers to the accompanying drawings.Although the description includes exemplary implementations, otherimplementations are possible and changes may be made to theimplementations described without departing from the spirit and scope ofthe invention. The following detailed description and the accompanyingdrawings do not limit the invention. Instead, the scope of the inventionis defined by the appended claims.

This display device comprises a display, a support portion for rotatablysupporting the display, and at least one engaging portion for performingengagement when the display is rotated to a predetermined usingposition, the engaging portion being constructed so as to perform theengagement in plural engaging places when the display is rotated to thepredetermined using position. The above engaging portion may be arrangedat one end of the display, and may be also arranged at both ends of thedisplay.

In this construction, the engaging portion or an engaging means isconstructed so as to perform the engagement in the plural engagingplaces when the display is rotated until the using position.Accordingly, in this construction, load to the engaging place forobtaining the same holding force can be reduced, and the load in theengaging place can be reduced, and durability of the engaging portioncan be improved. Further, in this construction, GND force is improved byincreasing the engaging places, and electric performance can beimproved.

Further, the engaging portion may have a fixing member and a rotatingmember rotated in accordance with the rotation of the display, and oneof the fixing member and the rotating member may have plural convexportions, and the other may have plural concave portions, and the pluralconvex portions and the plural concave portions may be arranged so as tobe engaged with each other. Since the plural convex portions arearranged, this construction can reduce the load to the convex portionand can reduce wearing of the convex portion and can improve durabilityof the engaging portion.

Further, the plural concave portions arranged so as to be separated inthe circumferential direction may be provided corresponding to each ofthe convex portions in the engaging portion. The display can be used bythis construction in plural using positions.

Further, the positions of the plural convex portions in the engagingportion may be set to positions in which the distances from the centerof rotation of the rotating member are different from each other. Inthis construction, a construction able to use the display in the pluralusing positions can be provided in a small space.

A ceiling mounting type display device is provided in another aspect.The ceiling mounting type display device has the above display device,and may be constructed so as to be mounted to a ceiling. Thisconstruction can improve durability of the engaging portion and can alsoimprove electric performance with respect to GND in the ceiling mountingtype display device of a vehicle, etc.

The display device of this embodiment will next be explained by usingthe drawings.

The display device of this embodiment is shown in FIGS. 1 to 6. First,the entire construction of the display device will be explained withreference to FIGS. 4 to 6. It is then returned to FIG. 1 and the detailsof the construction of the display device will be explained.

FIGS. 4 to 6 show the entire construction of the display device of thisembodiment. The display device 1 has a base portion 2 and a display 3.The display 3 is a planar display of liquid crystal, etc., and isrotatably supported to the base portion 2 by a hinge portion 4. Thehinge portion 4 corresponds to a support portion of the presentinvention.

The display device 1 of this embodiment is used for a vehicle, and isarranged in the ceiling of a vehicle room in postures shown in FIGS. 4to 6. In an arranging state, a mechanical portion of the base portion 2is hidden by the lining of the ceiling. FIG. 4 shows a full closingstate and FIG. 5 shows a semi-opening state and FIG. 6 shows a fullopening state. In the full closing state of FIG. 4, the screen of thedisplay 3 is directed to the ceiling, and the display is located in astoring position. When a release button 5 arranged in the display 3 ispushed, a lock is released and the display 3 can be rotated and openedas shown in FIGS. 5 and 6.

FIG. 1 is an exploded perspective view of the display device 1, andshows the display 3 and the hinge portion 4. The hinge portion 4 isconstructed by a right-hand hinge portion 6 and a left-hand hingeportion 7. The right-hand hinge portion 6 and the left-hand hingeportion 7 are respectively arranged on the right-hand side and theleft-hand side of the display 3.

The right-hand hinge portion 6 has a right-hand bracket 11 fixed to thebase portion 2, and a right-hand shaft 13 rotatably arranged in theright-hand bracket 11. The right-hand shaft 13 is fixed to a base endportion of the display 3. Similarly, the left-hand hinge portion 7 has aleft-hand bracket 15 fixed to the base portion 2, and a left-hand shaft17 rotatably arranged in the left-hand bracket 15. The left-hand shaft17 is fixed to a base end portion of the display 3.

Here, in the following explanation, the side close to the center of thedisplay 3 along a rotating axis X is called the inside, and the side farfrom the center of the display 3 is called the outside.

FIG. 2 is an exploded perspective view of the right-hand hinge portion6. The right-hand hinge portion 6 has the right-hand bracket 11, theright-hand shaft 13, a click washer 21, a spring plate 23 and a flatwasher 25 and these members are manufactured from iron.

The right-hand bracket 11 has an attaching portion 31 fixed to theunillustrated base portion, and a wall portion 33 perpendicular to theattaching portion 31. The right-hand shaft 13 is inserted into a hole 35of the wall portion 33. Thus, the right-hand shaft 13 is rotatablysupported. The hole 35 of the wall portion 33 functions as a bearing ofthe right-hand shaft 13.

The right-hand shaft 13 is fixed to the display 3 by an attachingportion 37 at the inside end. A flange 39 is arranged near an outsideend of the right-hand shaft 13. In a state in which the right-hand shaft13 is inserted into the hole 35 of the right-hand bracket 11, the clickwasher 21 is nipped by the flange 39 and the wall portion 33 of thebracket 11.

The click washer 21 has a disk shape, and the right-hand shaft 13 isinserted into a central hole of the click washer 21. The central hole ofthe click washer 21 has a shape engaged with the right-hand shaft 13.More specifically, two parallel straight line portions are arranged inthe central hole. These straight line portions are engaged with twoparallel planes of an end portion of the right-hand shaft 13. Thus, theclick washer 21 is engaged with the right-hand shaft 13, and is rotatedtogether with the right-hand shaft 13. The click washer 21 is slid withrespect to the right-hand bracket 11.

An outside end portion of the right-hand shaft 13 extends through theright-hand bracket 11 and is projected out. The spring plate 23 and theflat washer 25 are sequentially fitted to the projecting-out portion.The spring plate 23 and the flat washer 25 have a disk shape. Similar tothe click washer 21, the right-hand shaft 13 is inserted and engagedwith central holes of the spring plate 23 and the flat washer 25. Thus,the spring plate 23 and the flat washer 25 are also rotated togetherwith the right-hand shaft 13. The flat washer 25 maintains the axialposition relation between constructions of the right-hand hinge portion6. The right-hand bracket 11, the right-hand shaft 13 and the clickwasher 21 are mutually pressed by the spring plate 23.

The construction of the engaging portion or the engaging means in thisembodiment will next be explained. The click washer 21 has two armportions 41 extended in a radial shape. The two arm portions 41 arelocated on the opposite side with a hinge axis X as a center. A convexportion 43 is arranged in each arm portion 41 so as to be directed tothe right-hand bracket 11.

On the other hand, two concave portions 45, 47 are arranged in positionscorresponding to each convex portion 43 in the wall portion 33 of theright-hand bracket 11. The concave portions 45, 47 are constructed bythrough holes. In the concave portions 45, 47 and the convex portion 43,the distances from the rotating axis X are set to the same. The twoconcave portions 45, 47 are arranged correspondingly to each of the twoconvex portions 43. Accordingly, the total number of concave portions is4. The concave portions 45, 47 are located in positions shifted on thecircumference of a circle with the rotating axis X as a center.

The concave portions 45, 47 correspond to two using positions set in thedisplay device 1 of this embodiment. When the display 3 is located in afirst using position, the convex portions 43 face the first concaveportions 45. When the display 3 is located in a second using position,the convex portions 43 face the second concave portions 47.

When the convex portions 43 are located in positions shifted from theconcave portions 45 and the concave portions 47, the convex portions 43are interposed between the click washer 21 and the right-hand bracket11. Therefore, the arm portions 41 of the click washer 21 are flexed anddeformed. When the convex portions 43 reach the concave portions 45 orthe concave portions 47, the deformation of the arm portions 41 arerestored and the convex portions 43 are fitted into the concave portions45 or the concave portions 47 so that an engaging state is obtained.

Further, arc convex portions 49 are arranged in positions shifted fromthe concave portions 45, 47 in the click washer 21. The arc convexportions 49 are extended along a path through which the convex portions43 of the click washer 21 passes. Each arc convex portion 49 isconstructed by a flat portion and a taper portion (slope portion). Inthe arc convex portions 49, the convex portions 43 of the click washer21 are pushed up or lifted. Thus, the click washer 21 is deformed andbiases the right-hand bracket 11. This deformation increases torqueresisting the rotating movement of the display 3. The shape of the arcconvex portions 49 are set so as to generate torque for giving amoderate resisting feeling (responsive feeling) to an operator at anoperating time.

FIG. 3 is an exploded perspective view of the left-hand hinge portion 7.The left-hand hinge portion 7 has the left-hand bracket 15, theleft-hand shaft 17, the click washer 21, the spring plate 23 and theflat washer 25. Similar to the right-hand hinge portion 6, the left-handshaft 17 is also inserted into the left-hand bracket 15 in the left-handhinge portion 7. The click washer 21 is nipped between the left-handbracket 15 and the left-hand shaft 17. The spring plate 23 and the flatwasher 25 are fitted to the left-hand. shaft 17 on the opposite side ofthe left-hand bracket 15. Similar to the right-hand hinge portion 6, theconvex portions 43 are also arranged in the arm portions 41 of the clickwasher 21 in the left-hand hinge portion 7, and the concave portions 45,47 are arranged in the left-hand bracket 15. These portions constitutethe engaging portion. The construction of the left-hand hinge portion 7is similar to the construction of the right-hand hinge portion 6, andits detailed explanation is therefore omitted.

The construction of the display device 1 of this embodiment has beenexplained as mentioned above. Next, the operation of the display device1 of this embodiment will be explained.

First, the operation of the display device 1 at an opening time of thedisplay 3 will be explained. When a button 5 (FIG. 4) of the displaydevice 1 is pushed, the lock of the display 3 is released and thedisplay 3 can be rotated with the rotating axis of the hinge portion 4as a center. The tip of the display 3 is lowered downward to a certainextent by the weight of the display 3. The tip of the display 3 ismanually pushed down by a user, and the display 3 is further rotated(FIGS. 5 and 6).

At this time, in the right-hand hinge portion 6, the click washer 21 isrotated together with the right-hand shaft 13. The click washer 21 isrotated with respect to the right-hand bracket 11. When the display 3reaches the first using position, the two convex portions 43 of theclick washer 21 simultaneously reach the two concave portions 45 of theright-hand bracket 11, and are fitted and engaged with the two concaveportions 45. Similarly, in the left-hand hinge portion 7, the clickwasher 21 is rotated with respect to the left-hand bracket 15. When thedisplay 3 reaches the first using position, the two convex portions 43of the click washer 21 simultaneously reach the two concave portions 45of the left-hand bracket 15, and are fitted and engaged with the twoconcave portions 45. Thus, the display 3 is locked in the first usingposition.

When the tip of the display 3 is further pushed by a user, the display 3is further rotated. At this time, in the right-hand hinge portion 6 andthe left-hand hinge portion 7, the convex portions 43 of the clickwasher 21 are disengaged from the concave portions 45, and the clickwasher 21 is further rotated. When the display 3 reaches the secondusing position, the convex portions 43 of the click washer 21 reach theconcave portions 47. In each of the right-hand hinge portion 6 and theleft-hand hinge portion 7, the two convex portions 43 are simultaneouslyfitted and engaged with the two concave portions 47. Thus, the display 3is locked in the second using position.

Next, the operation of the display device 1 at a closing time of thedisplay 3 will be explained. When the display 3 is closed, the display 3is pushed by a hand of the user and is rotated. At this time, in theright-hand hinge portion 6 and the left-hand hinge portion 7, the convexportions 43 of the click washer 21 are disengaged from the concaveportions 47, and the lock state is released. When the display 3 isrotated, the convex portions 43 of the click washer 21 are fitted andengaged with the concave portions 45 of the bracket. When the display 3is further pushed, the convex portions 43 of the click washer 21 aredisengaged from the concave portions 45, and the display 3 is rotatedand reaches a storing position. When the display 3 reaches the storingposition, the lock is automatically operated and the display 3 is lockedin the storing position.

Here, in this embodiment, the engaging portion is arranged in each ofthe right-hand hinge portion 6 and the left-hand hinge portion 7. Ineach engaging portion, two engaging places opposed by 180 degrees arearranged. (In this embodiment, there are two sets of “two engagingplaces”. A first set is a pair of two concave portions 45. A second setis a pair of two concave portions 47.) Thus, in this embodiment, the twoengaging places are arranged. On the other hand, in the prior art, thenumber of engaging places is one. Accordingly, when this embodiment iscompared with the prior art, spring force to be given to the clickwasher 21 in order to obtain the same holding force can be set to halfin this embodiment. Accordingly, in this embodiment, load applied toeach engaging place at the hinge rotating time can be set to half. Inthe above example, when the convex portions 43 are pressed against thebracket wall portion 33 in a non-engaging state, the pressing forcebecomes half. Thus, wearing of the engaging place can be reduced and areduction in the holding force caused by the wearing can be prevented.

The above construction will be explained in further detail. When thenumber of engaging places is one, it is assumed that the magnitude ofload is a wearing generating level or more. In this case, the load ofeach engaging place can be set less than wearing generating level(critical value) by setting the number of engaging places to two in thisembodiment. Thus, the generation of the wearing can be substantiallyremoved. Accordingly, durability of the holding force can be set totwice or more by increasing the number of engaging places to two. Thus,reliability of twice or more can be secured.

Further, in the above embodiment, the number of contact places betweenmetals of the display and GND becomes two and GND points are increasedby setting the number of engaging places to two. Thus, the GND force isincreased and electric performance with respect to GND is improved.

Further, in this embodiment, two concave portions are arrangedcorrespondingly to one convex portion. However, three concave portionsor more may be also arranged with respect to one convex portion.Conversely, one concave portion may be also arranged with respect to oneconvex portion.

Further, in this embodiment, the engaging portions are arranged in thetwo hinge portions. However, the engaging portion may be also arrangedin only one hinge portion.

Further, in this embodiment, the convex portions are arranged in theclick washer as a rotating member, and the concave portions are arrangedin the bracket as a fixing member. In contrast to this, the convexportions may be arranged in the fixing member, and the concave portionsmay be arranged in the rotating member.

Next, other modified examples of the above embodiment will be explainedwith reference to FIGS. 7 to 10. The bracket and the click washer aretypically shown in FIGS. 7 to 10.

In FIG. 7, click washers 53 are arranged on both sides of the bracket51. Each click washer 53 has one arm portion 55. A convex portion 57 isarranged in the arm portion 55. The two click washers 53 are rotatedtogether with the display. When the display reaches a using position,the two convex portions 57 are fitted and engaged with the concaveportion 59 from both the sides of the bracket 51. The construction ofFIG. 7 may be arranged in the hinge portions on both sides of thedisplay, and may be also arranged in the hinge portion on one side (thisis similarly adopted in FIGS. 8 and 9).

Next, FIG. 8 shows a bracket 61 and a click washer 62. In FIG. 8, theclick washer 62 is constructed by two semi-disks of different radii. Armportions 63, 64 are arranged in the respective semi-disks, and convexportions 65, 66 are arranged in the arm portions 63, 64. Accordingly, inthe two convex portions 65, 66, the distances from the rotating axis Xare different from each other. In accordance with this difference,concave portions 67, 68 are also arranged in positions separated fromthe rotating axis X, and the distances from the rotating axis X in theconcave portions 67 and the concave portions 68 are different.

FIG. 9 is a modified example similar to FIG. 8. A bracket 71 and a clickwasher 72 are shown in FIG. 9. Two arm portions 73, 74 are arranged inthe click washer 72. The arm portion 73 and the arm portion 74 areperpendicularly arranged. The lengths of the arm portion 73 and the armportion 74 are different from each other, and the arm portion 73 islonger. A convex portion 75 of the arm portion 73 is located far fromthe rotating axis X in comparison with a convex portion 76 of the armportion 74. In accordance with this construction, the distances from therotating axis X in concave portions 77, 78 are different from each otherin the bracket 71.

In the above constructions, the radial positions of plural convexportions (distances from the center of rotation) are differently set.This construction is advantageous when the lock of plural stages(multi-angle lock) is realized in a small space as explained below. FIG.10 is a typical view of a click washer 81 and a bracket 82. In FIG. 10,the click washer 81 also has two arms 83, 84 of different lengths, andthe arms 83, 84 have convex portions 85, 86. The distances from therotating axis X in the convex portions 85, 86 are different from eachother.

In FIG. 10, the bracket 82 has two concave portion series (or rows). Thetwo concave portion series are four concave portions 87 a to 87 d andfour concave portions 88 a to 88 d. The concave portions 87 a to 87 dcorrespond to the convex portion 85, and the concave portions 88 a to 88d correspond to the convex portion 86. Accordingly, the distances of theconcave portions 87 a to 87 d from the rotating axis X are greater thanthe distances of the concave portions 88 a to 88 d from the rotatingaxis X. Further, in the concave portions 87 a to 87 d and the concaveportions 88 a to 88 d, the angles between the concave portions with therotating axis X as a center are the same. The angles (intervals) betweenthe concave portions are narrowly set.

In this embodiment, as shown in FIG. 10, the series of the concaveportions 87 a to 87 d and the series of the concave portions 88 a to 88d are partially overlapped. The concave portion 88 c is located on theradial inside between the concave portions 87 a and 87 b. Similarly, theconcave portion 88 d is located on the radial inside between the concaveportions 87 b and 87 c. Thus, the plural concave portions are arrangedin a small space.

In the above construction, when the click washer 81 is rotated togetherwith the display, the convex portions 85, 86 are engaged with theconcave portions 87 a, 88 a, and are subsequently engaged with theconcave portions 87 b, 88 b. Thus, the convex portions 85, 86 performthe engagement in four places, and the display is locked.

As mentioned above, in the construction of FIG. 10, the radii (radialpositions) of the convex portions 85, 86 are different, and the radii ofthe concave portion series for the multi-angle lock are different. Thus,the concave portion series can be overlapped, and the concave portioninterval can be reduced. The simultaneous engagement of plural places isrealized and the multi-angle lock is realized in a small space.

As mentioned above, the display device in accordance with thisembodiment has been explained. In accordance with this embodiment, theengaging portion is constructed so as to perform the engagement inplural engaging places when the display is rotated to the usingposition. In this embodiment, it is possible to reduce the load to theengaging place for obtaining the same holding force. Accordingly, theload in the engaging place can be reduced, and durability of theengaging portion can be improved.

Further, in this embodiment, the GND force is improved by increasing theengaging portions, and electric performance can be improved.

Further, in this embodiment, the bracket and the click washerrespectively correspond to the fixing member and the rotating member.The engaging portion has the fixing member and the rotating member. Oneof the fixing member and the rotating member has plural convex portions,and the other has plural concave portions. The plural convex portionsand the plural concave portions are arranged so as to be engaged.Accordingly, the load to the concave portion and wearing due to thisload are reduced by arranging the plural convex portions, and durabilityof the engaging portion can be improved.

Further, in this embodiment, the plural concave portions arranged so asto be separated in the circumferential direction are providedcorresponding to each of the convex portions. Thus, a phase differenceis formed and the display can be used in plural using positions.

Further, in this embodiment, with respect to the positions of the pluralconvex portions, the distances from the center of rotation of therotating member are different. Thus, as explained with reference to FIG.10, the construction able to use the display in the plural usingpositions can be provided with a small space in this embodiment.

Further, in this embodiment, the display device 1 is constructed so asto be mounted to the ceiling of a vehicle. The screen of the display 3is directed to the ceiling in the storing position, and the display 3hangs down from the ceiling in the using position. In such a ceilingmounting type display device, the display 3 is opened and closed at theusing time and a use terminating time. Further, the display 3 is alsoopened and closed when it is intended so as not to obstruct the viewfield of a driver at a backward advancing time of the vehicle.Accordingly, the number of opening and closing times of the display 3 isnecessarily increased. In this embodiment, the display device 1 is theceiling mounting type display device. In the display device mounted tothe ceiling, durability of the engaging portion is improved and GNDability can be improved.

Persons of ordinary skill in the art will realize that manymodifications and variations of the above embodiments may be madewithout departing from the novel and advantageous features of thepresent invention. Accordingly, all such modifications and variationsare intended to be included within the scope of the appended claims. Thespecification and examples are only exemplary. The following claimsdefine the true scope and spirit of the invention.

1. A display device comprising: a display; a support portion forrotatably supporting said display; and at least one engaging portion forperforming engagement when said display is rotated to a predeterminedusing position, said engaging portion being constructed so as to performthe engagement in plural engaging places when said display is rotated tosaid predetermined using position.
 2. The display device according toclaim 1, wherein said engaging portion has a fixing member and arotating member rotated in accordance with the rotation of said display,and one of said fixing member and said rotating member has plural convexportions, and the other has plural concave portions, and said pluralconvex portions and said plural concave portions are arranged so as tobe engaged with each other.
 3. The display device according to claim 2,wherein the plural concave portions arranged so as to be separated inthe circumferential direction are provided corresponding to each of theconvex portions in said engaging portion.
 4. The display deviceaccording to claim 3, wherein the positions of said plural convexportions in said engaging portion are set to positions in which thedistances from the center of rotation of said rotating member aredifferent from each other.
 5. A ceiling mounting type display devicehaving the display device according to claim 1 and mounted to a ceiling.